"""Structured JSON logging with OpenTelemetry trace correlation."""

from __future__ import annotations

import json

import logging

import os

import sys

from datetime import UTC, datetime

class _JSONFormatter(logging.Formatter):

"""Format log records as single-line JSON with OTel trace context."""

def format(self, record: logging.LogRecord) -> str:

entry: dict[str, str | int | float] = {

"timestamp": datetime.fromtimestamp(record.created, tz=UTC).isoformat(),

"level": record.levelname,

"module": record.module,

"message": record.getMessage(),

}

# Trace context injected by OTel logging instrumentation

entry["trace_id"] = getattr(record, "otelTraceID", "0")

entry["span_id"] = getattr(record, "otelSpanID", "0")

return json.dumps(entry, default=str)

def setup_logging(level: str | None = None) -> None:

"""Configure Python logging with structured JSON output and OTel correlation.

Reads ``LOG_LEVEL`` from the environment if *level* is not provided.

Args:

level: Logging level name (e.g. "INFO", "DEBUG"). Falls back to the

``LOG_LEVEL`` environment variable, then to ``"INFO"``.

"""

from opentelemetry.instrumentation.logging import LoggingInstrumentor

resolved_level = (level if level else os.getenv("LOG_LEVEL", "INFO")).upper()

# Instrument stdlib logging so trace/span IDs are injected

LoggingInstrumentor().instrument(set_logging_format=False)

root = logging.getLogger()

root.setLevel(resolved_level)

# Remove existing handlers to avoid duplicate output

root.handlers.clear()

handler = logging.StreamHandler(sys.stderr)

handler.setFormatter(_JSONFormatter())

root.addHandler(handler)